It is proposed that reproductive physiology and behavior be studied in male rats whose mothers consumed ethanol during pregnancy. A growing body of evidence suggests that alcohol affects the hypothalamic-pituitary-gonadal axis and reduces levels of gonadal hormones. The same hormones are ordinarily released during the perinatal developmental period. They are necessary for the sexual differentiation of multiple organ systems, including a variety of brain areas implicated in the control of sexual behavior. Accordingly, sexual development and behavior may be compromised in males that are prenatally exposed to ethanol. There are now comparatively few data regarding the reproductive consequences of fetal alcohol exposure. Thus, the objectives of these investigations are: 1) to measure testosterone production in the fetal testes of prenatally alcohol exposed males; 2) to quantify testosterone titers in ethanol exposed male fetuses at periods near birth; and 3) to study pubertal development and adult reproductive behavior and physiology in prenatally alcohol exposed male rats. Drinking during pregnancy is now recognized as a serious health problem. As there is now a growing appreciation that alcohol consumption is also associated with gonadal endocrine disturbances, the proposed studies may yield an animal model for unrecognized teratogenic properties of alcohol.